Examination of Witnesses (Questions 7720
- 7739)
7720. MR TAYLOR: My Lord, the Secretary
of State does know that; I told him myself.
7721. CHAIRMAN: Thank you very much.
Camden.
7722. MR TAYLOR: My Lord, I understand
that my learned friend Mr Clarkson has a statement to read out
on behalf of the London Borough of Camden.
The following Petition against the Bill was read:
The Petition of the London Borough of Camden.
MR PATRICK
CLARKSON appeared on behalf of
the Petitioner.
Sharpe Pritchard appeared as Agent.
7723. CHAIRMAN: Good morning, Mr Clarkson.
The Petition of the London Borough of
Camden
7724. MR CLARKSON: Good morning, my Lord.
We appear as formal Petitioners and there is a Petition that contains
issues which are now agreed. In passing, one paragraph, paragraph
29, refers to Tottenham Court Road eastern ticket hall. Any issues
which may be outstanding can be picked up in due course in the
Westminster Petition.
7725. The Petition, nevertheless, contains at
paragraph 20 an issue concerning groundborne noise and vibration/track
design. That has now been resolved as an issue, and my Lord may
I read this on to the minute? The copy you have been handed this
morning is the correct one.
7726. I will begin with the introduction. The
London Borough of Camden is the lead authority on the issue of
groundborne noise from the operation of Crossrail trains in tunnels,
supported on this matter by Westminster City Council, London Borough
of Islington, City of London and London Borough of Tower Hamlets.
I am sure that the Committee is now very familiar with what the
groundborne noise is. It can be described as the rumbling sound
that is heard inside buildings during the passage of trains in
tunnels.
7727. The basic point of dispute between the
collective local authorities and the Promoter is a simple difference
in the numerical standard that is to be applied in the case of
residential dwellings affected by groundborne noise. The Promoter
is relying on a design standard which permits levels of up to
40dB LAmax, S (slow) whereas the local authorities are looking
for a standard not to exceed 35dB LAmax, S. The issue was brought
forward by London Borough of Camden in the Commons Select Committee
proceedings and the ongoing discussions have resulted in agreement
of the wording of an Information Paper. However, this basic point
of difference has always been, and remains, a point of dispute
between the parties. So I now need to explain to the Committee
how this remaining and key point of dispute can have led to any
kind of agreement whatsoever.
7728. The Information Paper of interest to this
matter is D10, and its scope covers groundborne noise and vibration
during both construction and operation of the railway. London
Borough of Camden's primary concern relates to the standard that
has been adopted for the permanent railway, although many of the
points that have been discussed also apply to the operation of
the temporary construction railway that will service the tunnels
during their construction.
7729. Three of the local authorities affected
by the scheme have specific policies on train groundborne noise
inside dwellings, whilst others apply relevant planning conditions
on groundborne noise, and all are consistent in that they are
set at a maximum level of 35dB LAmax, S in each case. There are
no UK standards which relate to acceptable levels of groundborne
noise within dwellings, although design standards and guidance
published outside of the United Kingdom only supports the local
authorities' position that 35dB LAmax, S is a more appropriate
design aim.
7730. We say that the Promoter's position is
based largely on precedent, with the 40dB LAmax, S policy devised
and supported through formal proceedings by Mr Thornely-Taylor
on behalf of the Promoters of schemes including DLR, Thameslink,
JLE and CTRL. During the presentation of evidence to the House
of Commons Select Committee on this generic issue, London Borough
of Camden sought to guide the Committee through the history of
the adoption of 40dB LAmax, S as a design standard and to demonstrate
that in its opinion the scientific evidence to support its application
was poor, speculative and inconclusive, and that for those reasons
alone a more precautionary approach was justified. Mr Thornely-Taylor
has explained during these proceedings that in the case of JLE
and the London section of the CTRL there have been no complaints
to his knowledge, but more importantly that actual noise levels
are much lower than the design standard of 40dB LAmax, S. These
relatively recent flagship projects do not therefore shed any
light at all on whether 40dB LAmax, S is an acceptable level because
they evidently do not generate noise levels as high as this.
7731. On the basis of evidence put before the
House of Commons Select Committee by Petitioners on the need for
more stringent groundborne noise commitments the Promoter was
instructed to provide floating slab track or a similar technology
at certain locations along the route. This has resulted in the
Promoter reporting to London Borough of Camden in its letter dated
21 December 2007 that no residential properties along the tunnelled
sections of the route are predicted to experience groundborne
noise levels at or above 35dB LAmax, S at any location with the
caveat that the final track specification will not be determined
until the design of the tunnels is complete and their precise
position fixed. We have heard during these proceedings that possible
permitted changes to the tunnel alignment that could still occur
would, in the majority of cases, lead to less than a single decibel
of difference. On the face of it, therefore, the main objective
of the collective local authorities appears to have been indirectly
met.
7732. The Promoter does not alter its design
aim as presented in Table 1 of IP D10—and that is the third
version, for information—to reflect this, even though it
would not appear to impose any direct costs for it to do so.
7733. Camden remains concerned that the 40dB
LAmax, S standard does not withstand scientific scrutiny, but
in the interests of achieving an acceptable outcome for the affected
residents, and recognising the risk of attempting to force changes
to what appears to be an immovable policy for reasons unknown
by further representation in front of your Lordships, London Borough
of Camden has sought to secure its objectives by other means.
7734. The design aim criteria are of course
based upon predicted noise levels, and there was debate in the
other House about how the actual noise levels when the railway
is operational (the so-called "outturn" noise levels)
will relate to those predicted values, and what comfort any of
the Petitioners and other affected parties can take away from
these proceedings that they will actually be realised.
7735. However, the Promoter has rejected our
request to demonstrate compliance with its design aims by measuring
noise levels once the railway becomes operational.
7736. So that is the background to the agreed
approach.
7737. Our agreement to IP D10 version 3 is therefore
based on securing wording which can be summarised as follows.
The prediction model which is to be used for the detailed design
of the track system will conform to best practice and be in accordance
with the relevant International Standard on groundborne noise
prediction issued in 2005, showing full compliance with its guidance
on development, calibration, validation and verification. That
recites D10 paragraphs 4.1 and 5.1.
7738. That evidence of the model's accuracy
is provided to the local authorities for their comment—D10
paragraph 5.1.
7739. That the nominated undertaker will engage
in continued technical discussions relating to track design and
will take into account the local authorities' comments—D10
paragraph 4.2.
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